Just as fire engines arrive quickly at the scene to save people and property, the cells that fight viruses have to reach the site of an infection promptly to mount a protective response.
According to recent studies by University of Washington (UW) scientists, specialized types of white blood cells, a category called regulatory T cells, seem to help orchestrate this timely reaction to a virus invasion. Their findings appear in the April 24 edition of Science Express, a Web edition of selected Science papers published in advance of the print edition. The authors of the study, "Coordination of Early Protective Immunity to Viral Infections by Regulatory T Cells," are Jennifer M. Lund, senior fellow in immunology; Lianne Hsing, immunology graduate student; Thuy T. Pham, senior biology major; and Alexander Y. Rudensky, professor of immunology.
The Rudensky laboratory is noted for many contributions to the superhot field of regulatory T cells. These cells are important in controlling autoimmunity, a cellular self-attack that can lead to diseases like reactive arthritis. UW researchers and other scientists have shown that young mice deficient in regulatory T cells die from an aggressive form of autoimmunity that damages several organs.
Rudensky noted the great clinical interest in the therapeutic potential of regulatory T cells. Evidence is growing on the role of regulatory T cells in keeping the body's immune responses in check. Studies in lab animals suggest these cells might be harnessed to treat autoimmune diseases or reduce rejection of transplanted organs.
Researchers think that regulatory T cells might call a halt to immune responses as the body nears success in eliminating an infection. This suppression as the fight draws to an end would reduce tissue damage from robust immune responses.
But what happens early in infection" Does the immunity-suppressing function of regulatory T cells form an obstacle to organizing an attack on germs that have just invaded the body" Do regulatory T cells temporarily lose their suppression ability in reaction to viral-sensing mechanisms or other signals" In the recent Science Express study, researchers looked for a role for regulatory T cells during the start of a herpes simplex virus infection in mucus membranes.